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At least 595 records · Page 33Linked to original sources
PubMed1983

Disappearance of noradrenaline from different parts of the rabbit external ear following superior cervical ganglionectomy.

Following superior cervical ganglionectomy the noradrenaline tissue levels in the base of the rabbit external ear started to decrease after about 12 hours. About 4 hours later noradrenaline started to decrease about simultaneously in the middle piece and the tip. Within 24 hours after ganglionectomy the noradrenaline decreased rapidly in all three pieces. Thereafter the noradrenaline of the base piece was levelling off at about 15% of the normal whereas the noradrenaline in the two other pieces remained at about 40% of the normal. The results indicate that the adrenergic innervation of the ear is complex, but that the base piece is supplied with adrenergic axons that are shorter than those of the middle and tip pieces. Based on 1: the delay of 4 hours observed in the pattern of the noradrenaline disappearance between the base and the two other pieces, and II: the difference in distance between the three pieces of the ear and the superior cervical ganglion, a transport rate of a "protecting factor" could be discussed to be about 1-2 cm/h. The rate of axonal transport of dopamine-beta-hydroxylase in the rabbit sciatic nerve, was found to be within the same range, being about 2 cm/h.

Animals↗
PubMed1992

The vascular responses of the isolated perfused bovine external ear to exogenous histamine and 5-HT (serotonin).

The responses of the vasculature of isolated, non-sensitized, bovine external ears to histamine and serotonin (5-HT) were evaluated while they were being perfused with Krebs-Henseleit solution. Histamine (10(-5) mol/L to 5 x 10(-3) mol/L) and 5-hydroxytryptamine (5-HT) (10(-9) mol/L to 10(-2) mol/L) caused increased vascular resistance. Mepyramine (10(-7) mol/L), cimetidine (10(-5) mol/L) and atropine (10(-6) mol/L) inhibited the responses to histamine. The responses to 5-HT were inhibited by methysergide (10(-9) mol/L) and potentiated by morphine (10(-5) mol/L). These results suggest the presence of H1 and H2 histamine, and 5-HT receptors in bovine auricular vessels, all of which cause net vasoconstriction.

Animals↗
PubMed2005

Branchio-oculo-facial syndrome with the atresia of external ear.

We report an 8-year-old child with branchio-oculo-facial syndrome. He showed atresia of external ear, preauricular pit, maxillar and mandibular hypoplasia, mild ptosis on the left side, lacrimal duct obstruction, unilateral branchial cyst, hypertrichosis of the neck, left foot showed mild syndactily of fourth and fifth toes and dental abnormalities. His mother had pseudocleft of the lip which led to the diagnosis. The importance of serial observations in patients with rare genetic disorders is emphasized.

Branchio-Oto-Renal Syndrome↗
PubMed2005

Occurrence and population size of Malassezia spp. in the external ear canal of dogs and cats both healthy and with otitis.

Malassezia yeasts are commensal organisms of human and animal skin that occasionally act as pathogens; lipid-dependent species are associated with human skin disorders. The aim of this work was to evaluate the occurrence, risk factors and population size of different species of Malassezia in the external ear canal of dogs and cats with and without otitis externa. Between 2001 and 2003, 107 healthy animals (25 cats and 82 dogs) and 123 animals with chronic otitis exteirna (48 cats and 75 dogs) were clinically examined. Sterile cotton swabs were used to collect specimens from the external ear canal and culture tests and cytological examinations were performed to detect the presence and population size of Malassezia yeasts. Malassezia yeasts were isolated from 72.9% and 40% of the cats and from 57.3% and 28.0% of the dogs, with and without otitis externa, respectively. Malassezia was frequently isolated from animals under 5 years of age. The highest prevalence of positive samples was reported in winter for cats and in autumn for dogs. Dogs with pendulous ears showed a higher incidence of infection than dogs with erect ears. More Malassezia yeasts were recovered from animals with otitis (i.e. 59.6 colony forming units - CFUs - for cats and 66.0 CFUs for dogs) than healthy animals. Out of the 413 isolates obtained from animals with and without otitis, 403 (97.6%) were identified as M. pachydermatis and 10 (2.4%) as M. globosa. A statistical evaluation of the occurrence of Malassezia yeasts in dogs and cats revealed that predisposing factors for Malassezia infections are sampling period for cats, and type of ear for dogs. The largest population of Malassezia yeasts was detected in animals with otitis, suggesting a role in the occurrence of lesions.

Animals↗
PubMed1993

External ear canal schwannoma: an unusual case report.

To the best of our knowledge, this is the first report of external ear canal schwannoma in the English literature. Several detailed clinical and pathological features were demonstrated. We suggest that if a tender, encapsulated mass is found in the external ear canal, the diagnosis of schwannoma should be taken into consideration.

Ear Canal↗
PubMed1983

Autosomal dominant inheritance of conductive deafness due to stapedial anomalies, external ear malformations and congenital facial palsy.

Three siblings of Indian stock had profound bilateral conductive deafness with variable malformations of the external ears, stapedial abnormalities and facial paralysis. Their mother was similarly affected and inheritance of this private syndrome is evidently autosomal dominant. Some improvement of auditory function was obtained by surgical intervention in the middle ear.

Abnormalities, Multiple↗
PubMed1992

Keloids of the external ear.

Keloid formation is a rare complication of normal scar tissue development, also to the surgeon who performs surgery on the external ear. We are presenting 4 cases of keloid formation which occurred after ear piercing in 2 cases and after otoplasty in another 2 cases. The treatment of keloid formation caused difficulties and is not unequivocal. Therefore we wish to present our experiences as we have seen no cases of keloid formation after otoplasty described in the literature.

Adult↗
PubMed1986

CHARGE syndrome. Part I. External ear anomalies.

Ear anomalies and hearing loss are major components of CHARGE Syndrome. This paper describes the external ear anomalies found in this syndrome: short wide pinnae, often cupped and asymmetrical; distinctive triangular concha; discontinuity between the antihelix and antitragus; and 'snipped-off' portions of the helical folds. The patterns of anomalies are so distinctive that a preliminary diagnosis of CHARGE Syndrome can often be made on the basis of ear shape alone. Part II of this communication describes hearing loss in this syndrome.

Abnormalities, Multiple↗
PubMed1997

Facial palsy following trauma to the external ear: 3 case reports.

We report two children and a young adult who developed unilateral facial palsy shortly after injury to the external ear. In two instances the paralysis followed a prominent ear correction and in the other a laceration to the concha. The trauma-triggered facial palsy was most likely idiopathic although the anatomy of the facial nerve near the ear leads one to speculate on a possible pathway of a virally induced palsy (Bell's palsy). Each patient recovered over a period of 6 months.

Adult↗
PubMedDate not supplied

[Directionality of sound perception in the external ear of the dog].

Sound pressure level of tone was measured using a probe tube microphone at entrance to the dog's external meatus as a function of the azimuth of the sound source. It was demonstrated that directionality of the dog's external ear and corresponding values of interaural intensity differences (delta I) were gradually increased as the tone frequency raised from 0.5 to 40 kHz. Transfer in pinnae locations from lateral to frontal positions (one of the components of orientation reaction to an unexpected sound) resulted in some narrowing of directionality diagrams and in a displacement of their maxima towards the head midline. It was calculated that owing to this effects the extent of monotonic part of the function relating delta I and azimuth of a source were enlarged. The lateral pinnae position was suggested to be optimal for sound detection and the frontal one for localization of the moving sound source.

Acoustic Stimulation↗
PubMed1975

Extramammary Paget's disease of the external ear canal in association with ceruminous gland carcinoma. A case report.

A case of extramammary Paget's disease of the external ear canal in association with ceruminous gland carcinoma is presented. Extramammary Paget's disease is not uncommonly seen in regions where apocrine glands are prevalent, with or without underlying apocrine gland carcinoma. This is the first case, to our knowledge, of this association in the external ear canal.

Adenocarcinoma↗
PubMed1991

[External ear and abnormality of the urinary tract: a comparative study of 2 series (100 and 150 cases)].

Pinnal anomalies were observed in 46% of 150 children with urinary tract malformation. This ear feature was only recorded in 16 cases among 100 control children. The observation of abnormalities of the auricle (flattened structure of the pinna, deformed shape of the helix) should thus prompt to investigate a possible urinary tract malformation (vesico-renal reflux, mega-ureter). The identification of this disorder should occur as early as possible in order to perform corrective surgery before irreversible kidney damage. Any urinary disorder associated to atypical morphology of the external ear should lead to abdominal echography. Urinary infections, sometimes mistaken for upper respiratory tract infections, will sometimes provide a diagnostic lead, confirmed by cyto-bacteriological examination of urine. These observations further confirm the concomitant development of the external ear and urinary tract during embryogenesis.

Abnormalities, Multiple↗
PubMed1992

Characterization of external ear impulse responses using Golay codes.

This report explains the use of a complementary series, Golay codes, for probing the impulse response of the external ear. The codes are used to measure both the resonance of the human ear canal, using a sealed sound-delivery system, and to measure the transfer function of the pinna, using a free-field source. With two series of 512 binary numbers, the improvement in signal-to-noise ratio over a single impulse approaches the theoretical value of 30.1 dB [10 log(2.512)]. This technique has many of the same properties as maximal-length sequences [M. R. Schroeder, J. Acoust. Soc. Am. 66, 497-500 (1979)], but it has the added advantage that the sequence length is an integer power of two and is, therefore, particularly convenient to use with modern Fourier transform techniques.

Ear Canal↗
PubMed1984

Skin expansion as an adjunct to reconstruction of the external ear.

This case report illustrates the use of a Radovan tissue expander in a patient undergoing reconstruction of the upper two-thirds of the external ear. The expansion facilitated draping of the superior retro-auricular skin over the autogenous costal cartilage framework that was used for the skeletal reconstruction of the ear.

Adult↗
PubMed1986

Electrocochleography recorded non-invasively from the external ear.

A method is described to record cochlear evoked potentials in humans (ECochG) with a low impedance electrode on the external ear near the opening of the external auditory canal. A piezoelectric click stimulus was delivered to the ear through a polyethylene tube creating diminution of stimulus artifact and a signal delay. Wave forms resembling the cochlear microphonic (CM), summating potential (SP) and the eighth nerve action potential (N1) were differentially accentuated by changes in stimulation and recording parameters. The addition or subtraction of condensation and rarefaction click wave forms further clarified the N1 and SP, or the CM potential, respectively. These responses can be recorded with most contemporary evoked response equipment. This non-invasive method of ECochG lends itself well to the study of hearing loss and possibly other neurologic disorders, and may complement BAER examination especially when wave I is poorly delineated.

Audiometry, Evoked Response↗
PubMedDate not supplied

[Cholesteatoma of the external ear canal. A case report].

Cholesteatoma of the external ear canal is rare in otological practice. The case of a 62-year-old woman with local extension but scant symptoms or signs is reported. The literature is reviewed and the cause and treatment are discussed.

Aged↗